Abstract 2710: Aggressive Blood Pressure Lowering in Acute Intracerebral Hemorrhage is Associated with Perihematomal Hypoperfusion and Ischemia

Abstract

Introduction Optimal blood pressure control following acute ICH remains controversial. Blood pressure reduction may limit hematoma expansion, but may also cause hypoperfusion and further damage in the perihematomal region. We examined the relationship between the extent and speed of systolic blood pressure (SBP) lowering and perihematomal perfusion and ischemia. Methods Consecutive prospectively enrolled ICH patients with an MRI within 24 hours of symptom onset were included. Hourly SBPs were recorded from hospital presentation to MRI acquisition. Aggressive BP lowering was defined as: ≥30% reduction from baseline and at least one BP drop of ≥35mmHg/h. Hematoma volume was considered large if ≥30cc. FLAIR, GRE and perfusion weighted images were co-registered. T max maps were generated using RApid processing of PerfusIon and Diffusion (RAPID) software. The perihematomal region was defined by outlining the perihematomal edema on FLAIR images and subtracting the inner surface of blood products on the GRE generating a perihematomal rim. Statistical analyses were done using MATLAB. Results Twenty-seven patients were included (age: 62.7±17.9years; ICH volume: 26±26cc). Six of 27 (22%) patients experienced aggressive SBP lowering. Numbers reported: mean(IQR). The aggressiveness of SBP reduction was similar in large versus small hematomas: the percentage drop in SBP was 26% (10-33) vs. 21% (13-28), and the highest SBP drop was 43mmHg/h (29-56) versus 46mmHg/h (31-51), p=0.61 and p=0.92, respectively. Patients with SBP drops ≥35mmHg/h tended to have delayed bolus arrival (high T max ), 6.1s (4.8-7.7) versus 5.3s (3.5-5.6) (p=0.06), as did patients with SBP drops ≥30%,T max values 7.3s (6.2-8.6) versus 5.3s (3.6-6.2) (p=0.014). The effect was magnified in patients with a large (≥30%) and fast (≥35mmHg/h) drop in SBP, despite hematoma volumes being equivalent (p=0.01, Figure1 ). Five of 6 patients with aggressive SBP lowering had a T max >6s. Conversely, 7 out of 8 patients with modest SBP reduction had a T max ≤6s ( Figure2 ). Out of 11 patients with T max >6s, 8 had DWI lesions (73%) versus 4 of 16 (25%) with T max ≤6s (p=0.02). Conclusions: Aggressive SBP lowering in acute ICH is associated with high T max values in the perihematomal region irrespective of hematoma volume. High T max values in turn are associated with DWI lesions.